The effect of microwave radiation (2450 MHz) on the morphology and chromosomes of lymphocytes

Effects of microwave radiation have been examined on blood lymphocytes from Chinese hamsters that were irradiated 15 minutes each day during five consecutive days by 2450-MHz (CW) energy at power densities from zero to 45 mW/cm2. Measurements of absorbed energy were accomplished by twin-well calorimetry. One hour after sham or microwave radiation, blood was obtained by orbital hemorrhage and was cultured for one day if unstimulated or for three days if stimulated with phytohemagglutinin (PHA) to induce mitosis. Cultures were terminated with a brief colchicine treatment to arrest cells in metaphase; lymphocytes were then processed for morphological and cytogenetic analyses. Microwave radiation caused a transient, reversible and dose-dependent (albeit curvilinearly related) change in rate of blastic transformation of unstimulated lymphocytes. Rate of transformation was maximum at a power density of 30 mW/cm2, which is associated with a post-radiation body temperature of 39.3 °C. However, frequency of mitoses from PHA stimulation was reduced in irradiated samples. Both the enhancement of transformation and the inhibition of mitosis were evident at 5 mW/cm2. Autoradiography of cells labelled with 3H-thymidine showed no evidence of radiation-related DNA repair. Cytogenetic analysis demonstrated no difference in chromosomal aberrations in irradiated and control samples.